1. Technical Field
The present invention relates to a power semiconductor device and a method of manufacturing the same.
2. Description of the Related Art
Recently, in accordance with significant development of various forms of insulated gate bipolar transistor (IGBT) devices including an IGBT disclosed in Patent Document 1, applications have been widely used for a large capacity of industry and an electric car as well as a home appliance.
The largest advantage of the IGBT device is that the IGBT device performs a bipolar operation unlike a metal oxide semiconductor (MOS) field-effect transistor, wherein this bipolar operation generates conductivity modulation phenomenon to reduce series resistance depending on a raw material of a wafer at the time of a turn-on operation of the IGBT device, such that conduction loss is significantly reduced as compared with the MOSFET with respect to high withstand voltage and high current products, thereby making it possible to reduce power loss.
Therefore, in accordance with the recent trend of the IGBT technology, a technology capable of maximizing a conductivity modulation shape has been developed. To this end, a technology of accumulating hole carriers has been mainly used. The hole carriers are generated by holes injected from a P-collector layer and are gradually decreased toward an emitter layer, such that a ratio of the conduction loss is increased toward the emitter layer.
To solve this problem, a technology of reducing a width of a trench to trench (MESA) region, which becomes a final movement path of the hole carriers, to limit movement of the hole carriers has been applied.